Recently, fixtures for masking the regions other than the regions where soldering is to be performed have been widely used in the soldering process using a flow solder bath. Those masking fixtures (a.k.a. the dip pallet and the carrier pallet), however, are required to be periodically cleaned so as to avoid the degradation of the masking accuracy which may be degraded by the flux accumulated on the surface of the masking fixtures.
Typically, such cleaning may be performed by dipping the fixture into a solvent. Therefore, a larger amount of solvent may be required to be used. As a result, the cost may be increased and the operator's workload may be heavy.
There is a known technique to spray the solvent onto the cleaning objects without dipping. This method, however, may not overcome the problem that a larger amount of solvent is required.
To overcome the problem, there has been known a dry-type cleaning device that cleans the cleaning targets by contacting flying cleaning media with the cleaning targets. Patent Documents 1 and 2 disclose a cleaning method for cleaning the cleaning targets by flying the cleaning media in the circumferential direction in a cylindrical container (chassis) by the circulating air flow of compressed air and colliding the flying cleaning media with the cleaning targets disposed at the opening formed on the side surface of the cylindrical container.
In this method, however, the circulating air flow is caused by the compressed air. Therefore, when the cleaning targets are separated from the opening of the container (i.e. cleaning device), some of the cleaning media may leak through (be excluded from) the opening.
To overcome this problem, in Patent Document 1, a net member is provided at the opening to prevent the leakage of the cleaning media. However, due to the net member, the energy of the cleaning media when the cleaning media collide with the cleaning targets may be reduced. Further, the cleaning media may be stopped by the net member. As a result, the cleaning performance may be reduced.
Further, in Patent Document 2, a cap member that may cap (seal) the opening is provided to prevent the leakage of the cleaning media through the opening. This cap member, however, may force an operator to promptly operate the cap member upon separating the cleaning targets from the opening. As a result, extra workload and attention may become necessary, the device may have to have a complicated mechanism, the operation of the cleaning device may become much more difficult, and the cleaning device may be more likely to be broken.
To overcome at least one of the problems in the dry-type fixing device of the related art, the Applicant of the present invention has filed an invention of a dry-type cleaning device under Japanese Patent Application No. 2010-175667. In the dry-type cleaning device, suctioning unit is provided to be connected to a chassis of the dry-type cleaning device, so that when an opening of the chassis disposed at the cleaning targets, slice-like cleaning media are flown by a circulating air flow generated by air flowing from the outside of the chassis into the chassis through an air path of the suctioning unit and the cleaning media remain within the chassis by providing, for example, a net-like porous unit that passes air and dust in the chassis but does not pass the cleaning media, so that the circulated flying of the cleaning media can be continued by the circulating air flow.
According to the dry-type cleaning device, when the opening of the chassis is separated from the cleaning targets, the circulating air flow may disappear because the internal pressure at the opening becomes substantially equal to the atmospheric pressure, and due to the negative pressure caused by suctioning air, much air is introduced into the chassis through the opening. As a result, the cleaning media remain in the chassis by being adsorbed on the porous unit and do not leak from the opening.